Which solution meets these requirements?
Update the Amazon Cognito identity pool to assume the proper IAM role for access to the protected content.
Update the S3 ACL to allow the application to access the protected content.
Redeploy the application to Amazon S3 to prevent eventually consistent reads in the S3 bucket from affecting the ability of users to access the protected content.
Update the Amazon Cognito pool to use custom attribute mappings within the identity pool and grant users the proper permissions to access the protected content.
Explanations:
Updating the Amazon Cognito identity pool to assume the proper IAM role allows authenticated users to receive temporary security credentials that grant them permissions to access the protected S3 bucket. This is the standard approach to authorize access based on the user’s identity.
Updating the S3 ACL (Access Control List) is not the best practice for granting access. ACLs are less flexible and harder to manage than IAM policies. Additionally, relying on ACLs can lead to security misconfigurations. IAM roles are preferred for access management.
Redeploying the application to Amazon S3 does not address the issue of user access permissions. The errors reported by users are likely related to permissions rather than consistency issues, which means redeployment will not solve the underlying access problem.
While custom attribute mappings in the Cognito identity pool could help manage user attributes, this option does not directly address the permission issue needed to access the protected content in S3. Permissions should be managed through IAM roles associated with the identity pool rather than custom attributes.
From my perspective, the answer is:
Update the Amazon Cognito identity pool to assume the proper IAM role for access to the protected content.